1. Field of the Invention
Combustion engine accessories
2. Description of the Prior Art
Occasionally a descriptive term in this application may be shortened so as to recite only a part rather than the entirety thereof as a matter of convenience or to avoid needless redundancy. In instances in which that is done, applicant intends that the same meaning be afforded each manner of expression. Thus, the term fuel flow interference needle (31) might be used in one instance but in another, if meaning is otherwise clear from context, expression might be shortened to interference needle (31) or merely needle (31). Any of those forms is intended to convey the same meaning. The term attach or fasten or any of their forms when so used means that the juncture is of a more or less permanent nature, such as might be accomplished by nails, screws, welds or adhesives. Thus it is stated herein that the frontal chamber complement (4), where threaded bolts are employed for the purpose, is attached to the rear chamber complement (5). A connection in which one object is easily removed from another is described by the word emplace, as where it is stated herein that an object comprising operable adjustment means (300) employed for needle advancement and retraction is emplaced in the tunnel (42) to turn a threaded adjusting block (46). Employment of the words connect or join or any of their forms is intended to include the meaning of both in a more general way.
The term rigid emplacement denotes a connection other than by attachment which, nevertheless, permits separation only with great difficulty or torturous manipulation. It is accordingly stated herein that the anchoring of the knurled throttling cable end (503) within the cable end trap (509) is a connection of rigid emplacement.
The word multiply is not used herein as a verb, as often otherwise employed, but rather, as an adjective. Thus, where it is stated that carburetion is controlled in part by needling fuel jet (800) penetration by a multiply beveled fuel flow interference needle (31), meaning that more than one beveled area is present thereon (31).
The word comprise may be construed in either of two ways herein. A generic term used to describe a given one of a number of specific elements is said to comprise it, thereby characterizing the specific element with equivalency in meaning for the generic term. Thus, throttling cable anchoring means (502) may be said to comprise a knurled end (503), meaning that in the particular case, the means (502) is such an end (503). However, the word comprise may also be used to describe a feature which is part of the structure or composition of a given element. Thus, a carburetor chamber (1) may be said to comprise D-shaped configuration (2), meaning that the structure of the chamber (1) is such as to have the D-shape (2) as a feature of its structure. The meaning in the respective cases is clear from context, however. Accordingly, modifying words to clarify which of the two uses is the intended one seem unnecessary.
Terms relating to physical orientation such as up, down, higher and lower refer to carburetion assembly positioning in the manner in which it is typically mounted in a vehicle and consistent with the manner the subjects of this application are shown in the drawings. Thus, the throttling gate (41) is frequently spoken of as being raised or lowered and portions of the chamber (1) are referred to as the top or bottom thereof (1).
The terms effectually open and effectually closed are used herein with reference to adjustments in height of the throttling gate (41). The gate (41) is stated herein to effectually open and effectually close the chamber (1). The use of such terminology acknowledges the fact that even when the gate (41) is brought to its (41) lowest point within the chamber (1), a small opening necessary to allow the flow of sufficient air for engine idling remains. Although the chamber's (1) closure may not, therefore, be complete, it may correctly be said to be effectually so. Conversely, although the gate (41) may have not been brought completely to the top of the chamber (1) upon throttling cable (500) retraction, maximum airflow may, nevertheless, have been attained. At that height, the gate (41) is stated herein to be effectually open.
Although carburetion has been known since the last century, the never ending search for better efficiency and improved performance continues today.
The historical development of the Venturi principle--establishing that air speeds up when passed through a portion of a duct which has been narrowed--has led to the sculpting of carburetion chambers so as to confer upon the walls thereof the convexity which will accommodate the principle. Despite that and other redesign undertakings, however, carburetion problems remain. Despite the expectation that performance should increase proportionately to operable throttle advance, it has been observed that the rate of increase levels off or even drops when engine throttling is taken to the higher range. In stressed circumstances such as mountain driving where the air is thinner, carburetion problems become aggravated. Acquiring a larger carburetor to address them unfortunately results in a tradeoff at mid and lower range carburetion levels.
Typically, carburetors comprise a sliding mechanism--an airflow obstructor (400)--controlled operationally by retraction or extension of a throttling cable (500). The cable (500) is configured with anchoring means (502), discussed further ante, so that when retracted, the the airflow obstructor (400) is tugged open to allow therethrough the passage of air. The mixture of air and fuel is ducted to the engine's combustion chambers.
To reduce airflow and accordingly, fuel combustion, the sliding obstructor (400) is allowed effectually to close off or restrict airflow. That is accomplished by a gate spring (550) which upon expansion, forces the obstructor (400) across the carburetor chamber. Thus, the obstructor (400) is biased closed and continual operator effort or tethering means of some sort is required to keep the chamber open.
When effectually closed, the movable obstructor (400) is generally configured to permit the passage of a smaller volume of air, an amount just sufficient to support engine idling.
The fuel enters the chamber through one or more fuel jets. As the air passes through the chamber it creates a partial vacuum--particularly in a sector thereof (701) configured with Venturi convexity--which at a given level draws the fuel along with it.
It is generally recognized that carburetors comprise performance characteristics ranging from low level to high level, corresponding with cross sectional airflow access area (750) causally associated with throttling cable (500) disposition ranging from idling status to full retraction.
An examination of a typical chamber from either of its ends, discloses that as the throttling cable (500) is retracted, effectually opening the sliding or otherwise movable obstructor (400), the cross sectional carburetor airflow access area (750) is enlarged and engine performance is enhanced. Additional throttle retraction increases that area (750) even more but once the obstructor (400) is effectually opened, being raised to a point beyond half way, the increase in engine performance becomes negligible and fails to correspond proportionately with the increased volume of carbureted air.
This effect is often taken for granted by vehicle operators and considered merely to be a limitation inherent in the engine. A crucial factor, however, lies in the fact that the shape of the chamber itself--more or less symmetrically tubular--presents an airflow access area (750) which enlarges only a very small amount as the airflow obstructor (400) effectually opens a considerable amount.
One may readily visualize this by observing the curvature or arcuitry of the top of the circle circumferentially describing the area (750). While the sliding obstructor (400) moves along a linear continuum as it (400) is effectually raised or opened, the uppermost portion of the circular airflow access area (750) increases only slightly and the rate of increase diminishes with every progression.
Seen this way, it should be readily recognized that as the sliding obstructor (400) is raised from an effectually closed position, exposing the bottom of the circular area (750), a small upward displacement of the obstructor (400) enlarges the circular area (750) considerably and the circularity or arcuitry widens. This phenomena necessarily occurs until the sliding obstructor (400) reaches the circle's half way point. The shaping of the carburetor chamber must, therefore, address more than that provided by Venturi convexity (701). The challenge is to alter in some manner the existing phenomena. It is for this reason that the sculpting of the chamber can become a fascinating endeavor.
In sports vehicles--snowmobiles and speedboats, for example--carburetor designs providing not only for constancy of efficiency at all carburetion stages but as well for quick acceleration response throughout all levels of operation are constantly sought after. Operational readjustments may be made, of course, to accommodate the problems as they arise during vehicle use. It is not an uncommon experience for an operator to contend with sluggish performance by spending 20 minutes resetting or retuning the carburetor by disassembling and adjusting parts which are virtually inaccessible. The task with snowmobiles is complicated by adverse winter conditions and with boats by buoyant instability upon the water. If attempted with a snowmobile in a remote area, as it sometimes is, the loss even one of the tiny components can be disastrous.
Laboratory tests demonstrate that conventional prior art combustion is generally incomplete. When seen during operation under strobe light observation, droplets of fuel are readily apparent in the carburetion chamber. It is widely recognized that a more complete atomization of the fuel provides a better mix with the air which, carried to the combustion chamber, enhances explosive power. Despite the several decades of carburetor development undertaken, no model has previously emerged which provides the strobed mist or cloud sans droplets in the carburetion chamber.
Engine performance for its own sake is obviously an important issue. Nonetheless, there are few things more exciting in sports vehicle operation than the quick burst of response one achieves from a carburetor of improved design; and there are few disappointments which exceed those experienced when such performance is absent. Unfortunately, as the fuel flow interference needle known to prior art is withdrawn from the needling fuel jet (800), the change in performance observed seems merely lackluster. Previous embodiments fail to provide the excitement experienced operating an engine which virtually leaps into a higher power stage. Characterizing the challenge presented, it would be particularly gratifying to create an interference needle which is shaped to confer these more or less sudden carburetion shifts.
If these needs for discontinuous stage-to-stage carburetion and enhanced proportional carburetion efficiency together could be addressed by reshaping the interference needle and reshaping the chamber, many types of sports vehicles as well as other engine operated devices could be made more saleable.
The needs or objectives pointed out supra thus far remain only partly addressed in the prior art. Some, such as that just immediately addressed, have not been met at all.